Telescoping adjustable pole

ABSTRACT

An adjustable ski pole having a clamping mechanism for locking the pole in a desirable position. An outer shaft telescopically receives an inner shaft which is engaged by a clamping mechanism. The clamping mechanism includes a housing having a first portion attached to the outer shaft and a split portion defining a longitudinal gap. A circumferential slot separates the split portion from the first portion along about half the circumference. The split portion has a first lug on one side of the gap and a second lug on the other side. A lever is pivotably connected to the first lug. A link is pivotably connected to the lever to define an off-center linkage. A pivot rod engages the second lug, and a threaded connector adjustably connects the link to the rod. When the lever is pivoted from the release position to the clamping position, the gap width is reduced.

CROSS-REFERENCE TO RELATED APPLICATION

The present application claims the benefit of U.S. Provisional Patent Application No. 61/095,900, filed Sep. 10, 2008, the disclosure of which is hereby expressly incorporated by reference in its entirety.

BACKGROUND

Telescoping adjustable length poles are known in the art. There are downhill adjustable ski poles, backcountry adjustable ski poles, trekking poles, and the like, that are available on the market. The purpose of such poles is to accommodate athletes, such as skiers or hikers, of different height. Another purpose is to accommodate exercising, such as skiing, under variable conditions, with a single set of adjustable length poles.

There are two types of clamping mechanisms used for adjustable length poles that are known in the art: internal and external mechanisms. Internal mechanisms are located on the inside of the outer tubing portion of the pole. Internal mechanisms allow for a lower profile pole, can offer a lower swing weight, and are less prone to catching or interfering with other nearby objects. However, internal mechanisms have serious disadvantages: typically, they have problems with slipping during use, or, conversely, they tend to lock the ski pole and hinder the user from loosening the mechanism to adjust the pole. The locking tendency may be caused by ice accumulation, for example by ice freezing in the mechanism, or ice lining the inside of the pole causing the mechanism to spin without engaging or loosening the clamp. Because the mechanism is internal, there is no easy way to access it in the field for maintenance.

External mechanisms are generally located on the outside of the pole, and have been developed to overcome performance issues of the internal mechanisms. Because an external mechanism is affixed to the outside of a pole, it is readily accessible for troubleshooting and maintenance. The key disadvantages of external mechanisms known in the art are that external clamping mechanisms tend to be more bulky and add swing weight to a pole, relative to internal mechanisms.

External clamping mechanisms may generally be divided into two types. A first type clamps the outer pole shaft to the inner pole shaft, and a second type is affixed to the outer pole shaft and clamps only around the inner pole shaft. The second type of external mechanism allows the use of composite materials for the outer tubing, whereas the first type generally requires that the outer pole shaft be formed from a material that can be flexed repeatedly and is fatigue resistant, such as an aluminum alloy. Therefore, because of the flexibility in using composite materials for the tubing, the second type of the clamping mechanisms is preferable. However, even the mechanisms of the second type that are known in the art have exhibited serious shortcomings related to the lack of locking force, low reliability, awkward handling, bulkiness, etc.

Therefore, there remains a need for improvements to adjustable length telescoping poles, including clamping mechanisms therefore.

SUMMARY

This summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This summary is not intended to identify key features of the claimed subject matter, nor is it intended to be used as an aid in determining the scope of the claimed subject matter.

A telescoping adjustable ski pole having a clamping mechanism for locking an inner shaft of the pole in a desirable position is disclosed. In one embodiment, the telescoping adjustable ski pole comprises an outer shaft having an open end, an inner shaft having a first end slidably disposed in the open end of the outer shaft; and a releasable clamping mechanism.

The releasable clamping mechanism includes a housing having a tubular portion attached to the open end of the outer shaft and a split portion extending axially from the tubular portion, the split portion defining a longitudinal gap having a gap width. The split portion comprises a first lug on a first side of the gap and a second lug on an opposite side of the gap.

The releasable clamping mechanism further includes a lever having a first end pivotably connected to the first lug at a first pivot, a second end defining a thumb panel having a concave inner surface, and an intermediate aperture disposed between the first end and the thumb panel and oriented substantially parallel to the first pivot. The lever is pivotable about the first pivot between a clamping position and a release position.

The releasable clamping mechanism also includes a link having a first end pivotably connected to the lever intermediate aperture at a second pivot and a base defining a base aperture therethrough, a pivot rod pivotably disposed through the second lug, and a threaded connector that extends through the base aperture and threadably engages the pivot rod through its intermediate threaded aperture.

When the lever is pivoted from the release position to the clamping position, a width of the longitudinal gap in the split portion reduces. The first and second pivots engaged with the lever define an off-center linkage such that the lever is retained in the clamping position.

In another embodiment, an adjustable ski pole comprises a tubular outer shaft having a first diameter, a tubular inner shaft having a second diameter smaller than the first diameter, so that the inner shaft slidably engages the outer shaft, and a clamping mechanism.

The clamping mechanism comprises a housing having a collar portion attached to the outer shaft and a tubular split portion extending away from the collar portion and slidably engaging the inner shaft. The tubular split portion of the housing has a longitudinal gap and comprises a first connecting member on a first side of the gap and a second connecting member on a second side of the gap. An upper section of the split portion is separated from the collar portion with a circumferential slot.

The clamping mechanism also includes a lever having a base portion pivotably attached to the first connecting member, a curved panel disposed away from the base portion, and an intermediate aperture between the base portion and the panel. The lever is movable between an engaged position, wherein the upper section of the split portion clampingly engages the inner shaft, and a released position, wherein the split portion does not clampingly engage the inner shaft. The clamping mechanism further includes a linking element having a first end pivotably attached to the lever intermediate aperture, and a second end pivotably attached to the second connecting member.

DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same become better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a fragmentary side view of a telescoping adjustable pole with a clamping mechanism in accordance with the present invention;

FIG. 2 is a front-right perspective view of the clamping mechanism shown in FIG. 1;

FIG. 3 is a rear-right perspective view of the clamping mechanism shown in FIG. 2;

FIG. 4 is an exploded view of the clamping mechanism shown in FIG. 2;

FIGS. 5A and 5B show different views of the housing for the clamping mechanism shown in FIG. 2; and

FIG. 6 is a cross-sectional view of the clamping mechanism shown in FIG. 2.

DETAILED DESCRIPTION

An embodiment of a telescoping adjustable pole having a clamping mechanism is described below.

FIG. 1 illustrates a telescoping adjustable ski pole 10 having an outer shaft 16 (shown in phantom), an inner shaft 18 (shown in phantom) slidably received by the outer shaft 16, and a clamping mechanism 20 for locking the inner shaft 18 at a desired position with respect to the outer shaft 16. The clamping mechanism 20 is fixedly attached to the outer shaft 16 and is shown in a clamping position that locks the inner shaft 18 relative to the outer shaft 16. The outer shaft 16 includes a conventional handle 14, as are known in the art. Although not shown in the FIGURES, it will be appreciated that the inner shaft 18 would conventionally include a basket or the like disposed near the distal end. One skilled in the art will recognize that more than two telescoping shafts may be used with additional clamping mechanisms 20, for example to provide a very compactable ski pole.

The clamping mechanism 20 is illustrated in detail in FIGS. 2-5. FIG. 2 is a front-right perspective view of the clamping mechanism 20, FIG. 3 is a rear-right perspective view of the clamping mechanism 20, FIG. 4 is an exploded view of the clamping mechanism 20, FIGS. 5A and 5B show different views of the housing for the clamping mechanism 20, and FIG. 6 is a cross-sectional view of the clamping mechanism 20.

Refer now to FIGS. 2 and 3, showing different views of the clamping mechanism 20. The clamping mechanism 20 is a releasable, off-center linkage system for clamping the telescoping pole's inner shaft 18 at a fixed longitudinal position with respect to the outer shaft 16. The clamping mechanism 20 includes: (i) a housing 30 having a tubular portion 32 that is fixedly retained on the outer shaft 16, and a split portion 34 that releasably engages the telescoping inner shaft 18; (ii) a lever 50 that is pivotably attached to the split portion 34 of the housing 30; and (iii) a link 80 having one end that is pivotably connected to the lever 50 and the other end pivotably connected to the housing 30. The inner shaft 18 extends through the split portion 34 to telescopically engage the outer shaft 16. When the lever 50 is in the clamping position shown in FIGS. 2 and 3, it locks the inner shaft 18 at a desired adjustment.

Refer now also to FIG. 4, which shows an exploded view of the clamping mechanism 20. The tubular portion 32 of the housing 30 receives the end of the outer shaft 16 and is fixed thereto. For example, the housing 30 may be retained on the outer shaft 16 by a friction fit, an interference fit, with an adhesive material and/or using conventional attachment hardware (not shown). The tubular portion 32 optionally includes an inwardly-disposed flange or stop 31 that is sized to abut a top edge of the outer shaft 16.

Refer now also to FIG. 5A, which shows a front view of the housing 30 in isolation. The split portion 34 of the housing 30 is integral with the tubular portion 32, and extends axially from the tubular portion 32. The split portion 34 is generally a split tubular member sized to slidably receive the inner shaft 18, and having a longitudinal gap 36 along the entire length of the split portion 34.

A first lug 38 extends outwardly from one side of the gap 36, defining a first axial aperture 39 therethrough. A pair of second lugs 40 extend outwardly from the opposite side of the gap 36, defining a second axial aperture 41.

A circumferential slot 42 extends circumferentially around the housing 30 between the tubular portion 32 and the split portion 34. As will be appreciated from

FIG. 4, the section of the split portion 34 supporting the first lug 38 comprises a reduced-thickness panel 44. In this embodiment, the circumferential slot 42 extends for at least half the circumference of the split portion 34. The housing 30 is formed form an elastic semi-rigid material, for example a semi-rigid polymer, such that the split portion 34 can be compressed by narrowing the longitudinal gap 36. In particular, an upper section 46 of the split portion 34 is supported only along a longitudinal side. The upper section 46 is essentially cantilevered and curved to approximately match the curvature of the housing split portion 34. The upper section 46 can therefore flex inwardly with ease, relative to the lower section 47 of the split portion 43. It will now be apparent from the FIGURES that the clamping mechanism 20 operates by urging the upper section 46 of the split portion 34 inwardly to clamp the inner shaft 18, or releasing the upper section 46 to release the clamping force on the inner shaft.

The lever 50 includes a thumb panel 52 and base portion 54 comprising spaced apart arms 56 having axially aligned apertures 58 therethrough. As will be apparent from FIG. 4, the arms 56 are spaced apart to receive the first lug 38 therebetween. The lever 50 is pivotably attached to the first lug 38 with a first pivot 60 that passes through the axially aligned apertures 58, and the first axial aperture 39.

The base portion 54 of the lever 50 further comprises an intermediate aperture 62 disposed near the thumb panel 52 and oriented generally parallel to the axially aligned apertures 58.

The thumb panel 52 preferably is curved, having a concave inner surface that matches a convex outer surface of the housing 30. In one embodiment (not shown) the thumb panel 52 extends axially beyond the end of the housing 30 to form a ledge such that the lever 50 overhangs the housing 30. This configuration provides a small ledge to push against so as to assist in gloved operation of the clamping mechanism 20. As seen most clearly in FIG. 6, the lever thumb panel 52 may include an end tab portion 53 that is oriented to extend away from the housing 30 when in the clamped position, to facilitate releasing the lever 50.

Still referring to FIG. 4, the link 80 is a generally U-shaped element having spaced apart arms 82 and a connector portion 84 therebetween. The arms 82 are spaced to receive the base portion 54 of the lever 50 therebetween. The arms 82 include axially aligned apertures 86. The link 80 is pivotably connected to the lever 50 by a second pivot 90 that extends through the axially aligned apertures 86 in the link 80 and the intermediate aperture 62 in the lever 50. The connector portion 84 of the link 80 includes a through hole 88, discussed below. A rod 92 having a transverse threaded aperture 94 therethrough is inserted through the second axial apertures 41 in the second pair of lugs 40 on the housing 30. A threaded connector such as a bolt 96 extends through the through hole 88 in the connector portion 84 of the link 80, and engages the transverse threaded aperture 94 in the rod 92.

Refer now also to FIG. 5B, which shows a back view of the housing 30. The split portion 34 further comprises spaced-apart circumferential ribs 48 disposed generally on opposite ends of the split portion 34. The ribs 48 stiffen the lower section 47 of the split portion 34. Moreover, as will be best appreciated by also referring to FIG. 2, the circumferential ribs 48 define a channel therebetween that partially receives the distal end of the lever 50 to protect the lever 50 from inadvertent release or the like. The channel therebetween also provides a convenient guide for the user to be able to engage the end of the lever 50, e.g., to release the lever 50. It will be appreciated that this is particularly advantageous for users who will typically be wearing gloves.

Refer now again to FIG. 4. To assemble the clamping mechanism 20, the lever 50 is pivotably attached to the first lug 38 on the housing 30 by inserting the first pivot 60 through apertures 58 in the lever 50, and aperture 39 in the first lug 38. The link 80 is pivotably attached to the lever 50 by inserting the second pivot 90 through apertures 86 in the link 80 and intermediate aperture 62 in the lever 50. The link 80 is also connected to the housing 30 by inserting rod 92 through apertures 41 in the second lugs 40, and inserting the bolt 96 through the through hole 88 in the link 80, and threadably engaging the threaded aperture 94 in rod 92. The tubular portion 32 of the housing 30 is fixed to the outer shaft 16. The inner shaft 18 is slidably inserted through the housing 30 to telescopingly engage the outer shaft 16.

Refer now to FIG. 6, which shows a cross section of the clamping mechanism 20 generally through a centerline of the mechanism 20. The operation of the clamping mechanism 20 can now be understood. When the lever 50 is in the clamping position shown, the split portion 34 of the housing 30 is biased firmly against the inner shaft 18, thereby locking the axial position of the inner shaft 18 relative to the outer shaft 16. When the lever 50 is in the release position (shown in phantom) the split portion 34 is not biased towards the inner shaft 18, and therefore the user can adjust the axial position of the inner shaft 18.

It will be appreciated that the tubular portion 32 of the housing is simply fixed to the outer shaft 16, and the clamping mechanism 20 clamps only around the inner shaft 18. In particular, the clamping mechanism 20 performs the task of locking the ski pole 10 in a desired adjustment. Moreover, when the clamping mechanism 20 is in the clamping or locked position, the inner shaft 18 is engaged about substantially it's entire periphery, providing good locking performance, and relatively uniform clamping stresses in the inner shaft 18. This construction is particularly suited to forming the outer and inner shafts 16, 18 from a composite material. Composite construction of the outer and inner shafts 16, 18 enables the ski pole 10 to be very light weight, while providing the required structural performance. Therefore the ski pole 10 can have a swing weight.

Another aspect of the disclosed embodiment is that the split portion 34 of the housing 30 which engages only the smaller diameter inner shaft 18, may be of smaller diameter than the tubular portion 32 which engages the outer shaft 16. This provides a more compact construction.

While illustrative embodiments have been illustrated and described, it will be appreciated that various changes can be made therein without departing from the spirit and scope of the invention. 

1. A telescoping adjustable ski pole, comprising: an outer shaft having an open end; an inner shaft having a first end slidably disposed in the open end of the outer shaft; and a releasable clamping mechanism comprising: a housing having a tubular portion attached to the open end of the outer shaft and a split portion extending axially from the tubular portion, the split portion defining a longitudinal gap having a gap width, the split portion further comprising a first lug on a first side of the gap, and a second lug on an opposite side of the gap; a lever having a first end pivotably connected to the first lug at a first pivot, a second end defining a thumb panel having a concave inner surface, and an intermediate aperture disposed between the first end and the thumb panel and oriented substantially parallel to the first pivot, the lever being pivotable about the first pivot between a clamping position and a release position; a link having a first end pivotably connected to the lever intermediate aperture at a second pivot and a base defining a base aperture therethrough; a pivot rod pivotably disposed through the second lug, the pivot rod having an intermediate threaded aperture; and a threaded connector extending through the base aperture and threadably engaging the pivot rod intermediate aperture, wherein pivoting the lever from the release position to the clamping position reduces a width of the gap, and wherein the first and second pivots define an off-center linkage such that the lever is retained in the clamping position.
 2. The telescoping adjustable ski pole of claim 1, wherein the split portion of the housing is separated from the tubular portion by a circumferential gap around at least half of the circumference of the housing.
 3. The telescoping adjustable ski pole of claim 1, wherein the split portion of the housing defines a reduced thickness panel portion that supports the first lug.
 4. The telescoping adjustable ski pole of claim 1, wherein the split portion of the housing is recessed from the tubular portion of the housing.
 5. The telescoping adjustable ski pole of claim 1, wherein the gap width in the clamping position is adjustable by threadably adjusting the threaded connector in the pivot rod intermediate aperture.
 6. The telescoping adjustable ski pole of claim 1, wherein the split portion of the housing further comprises at least one circumferential stiffening ridge extending part way around the split portion.
 7. The telescoping adjustable ski pole of claim 1, wherein the thumb panel concave inner surface conforms to a convex outer surface of the split portion of the housing.
 8. The telescoping adjustable ski pole of claim 1, wherein the thumb panel of the lever comprises a ledge portion that overhangs the split portion of the housing.
 9. The telescoping adjustable ski pole of claim 1, wherein the outer shaft and the inner shaft are made of composite materials.
 10. The telescoping adjustable ski pole of claim 9, wherein the clamping mechanism is formed from a semi-rigid polymer.
 11. The telescoping adjustable ski pole of claim 10, wherein the tubular portion of the housing is fixedly attached to the outer shaft with an adhesive.
 12. The telescoping adjustable ski pole of claim 1, wherein the ski pole is a trekking pole.
 13. An adjustable ski pole comprising: a tubular outer shaft having a first diameter; a tubular inner shaft having a second diameter smaller than the first diameter, wherein the inner shaft slidably engages the outer shaft; and a clamping mechanism comprising: a housing having a collar portion attached to the outer shaft and a tubular split portion extending away from the collar portion and slidably engaging the inner shaft, the tubular split portion having a longitudinal gap, a first connecting member on a first side of the gap and a second connecting member on a second side of the gap, and further wherein an upper section of the split portion is separated from the collar portion with a circumferential slot; a lever having a base portion pivotably attached to the first connecting member, a curved panel disposed away from the base portion, and an intermediate aperture between the base portion and the panel; and a linking element having a first end pivotably attached to the lever intermediate aperture, and a second end pivotably attached to the second connecting member; wherein the lever is movable between an engaged position wherein the upper section of the split portion clampingly engages the inner shaft, and a released position wherein the split portion does not clampingly engage the inner shaft.
 14. The adjustable ski pole of claim 13, wherein the circumferential slot extends around at least half of the circumference of the collar portion.
 15. The adjustable ski pole of claim 13, wherein the split portion of the housing defines a reduced thickness panel portion that supports the first connecting member.
 16. The adjustable ski pole of claim 13, wherein the split portion is recessed from the collar portion.
 17. The adjustable ski pole of claim 13, wherein the second end of the linking element includes a through hole and is pivotably attached to the second connecting member with a threaded connector that extends through the through hole and threadably engages a threaded aperture in a pivot rod disposed through the second connecting member.
 18. The adjustable ski pole of claim 17, wherein a width of the longitudinal gap in the engaged position is adjustable by threadably adjusting the threaded connector in the pivot rod threaded aperture.
 19. The adjustable ski pole of claim 13, wherein the split portion further comprises at least one circumferential stiffening ridge extending part way around the split portion.
 20. The adjustable ski pole of claim 13, wherein the curved panel of the lever comprises a concave inner surface that conforms to a convex outer surface of the split portion.
 21. The adjustable ski pole of claim 20, wherein the curved panel of the lever further comprises a ledge portion that overhangs the split portion.
 22. The adjustable ski pole of claim 13, wherein the tubular outer shaft and the tubular inner shaft are made of composite materials.
 23. The adjustable ski pole of claim 13, wherein the clamping mechanism is formed from a semi-rigid polymer.
 24. The adjustable ski pole of claim 13, wherein the collar portion is fixedly attached to the tubular outer shaft.
 25. The adjustable ski pole of claim 13, wherein the ski pole is a trekking pole. 